Computer users are accustomed to using a mouse and keyboard as a way of interacting with a personal computer. While personal computers provide a number of advantages over written documents, most users continue to perform certain functions using printed paper. Some of these functions include reading and annotating written documents. In the case of annotations, the printed document assumes a greater significance because of the annotations made on it by the user. One of the difficulties, however, with having a printed document with annotations is the need to have the annotations subsequently entered back into the electronic form of the document. This requires the original user or another user to wade through the annotations and enter them into a personal computer. In some cases, a user will scan in the annotations and the original text, thereby creating a new document. These multiple steps make the interaction between the printed document and the electronic version of the document difficult to handle on a repeated basis. Further, scanned-in images are frequently non-modifiable. There may be no way to separate the annotations from the original text. This makes using the annotations difficult. Accordingly, an improved way of handling annotations would be desirable.
One technique for capturing handwritten information is by using an image capturing pen whose location may be determined during writing. One image capturing pen that provides this capability is the Anoto pen by Anoto Inc. This pen functions by using a camera to capture an image of paper encoded with a predefined pattern. An example of the image pattern is shown in FIG. 11. This pattern is used by the Anoto pen to determine a location of the pen on a piece of paper (or other positionally encoded medium).
A user may wish to access and annotate any one of a number of digital documents, which may be further specified by a document version. Moreover, an associated paper document is typically partitioned into a number of pages, which may be hundreds of pages. An application should know the particular page of a stroke (ink) to associate the stroke to the paper document. Once the page is identified, the location of the stroke on the page may be determined.
Documents may contain particular regions, such as fields of a form, that a user may interact with via a digital pen. It would be desirable to associate various local metadata values with respective regions of an embedded interaction code document to facilitate determining which region of a document a user is interacting with.